Deryck wrote:

I've got a bed side lamp which, in normal operation, if I touch the base
once it comes on, I touch it again it gets brighter, I touch it again it
gets brighter still, I touch it again and it turns off. Except now, after
changing the bulb, it is always on and at the brightest setting. Before I
cut the flex and put a switch in it can anyone suggest what the fault may be
and how it could be repaired? I could just sling it and buy another but it
is one of a matching pair so I would probably end up buying 2.

TIA,

Deryck

My guess is that it doesn't like the new bulb. What sort of bulb was
in it before? Conventional or Enery Saving (CFL)? What wattage?
What sort have you put in it now?
As an experiment you could try a boring old conventional bulb just to
check.

I've X-posted to uk.d-i-y as there are many posters there who might be
able to help.

Calvin wrote:
Deryck wrote:

I've got a bed side lamp which, in normal operation, if I touch the
base once it comes on, I touch it again it gets brighter, I touch it
again it gets brighter still, I touch it again and it turns off.
Except now, after changing the bulb, it is always on and at the
brightest setting. Before I cut the flex and put a switch in it can
anyone suggest what the fault may be and how it could be repaired? I
could just sling it and buy another but it is one of a matching pair
so I would probably end up buying 2.

TIA,

Deryck

My guess is that it doesn't like the new bulb. What sort of bulb was
in it before? Conventional or Enery Saving (CFL)? What wattage?
What sort have you put in it now?
As an experiment you could try a boring old conventional bulb just to
check.

I've X-posted to uk.d-i-y as there are many posters there who might be
able to help.

The triac probably went short-circuit if the old bulb blew.
It is usually a metal-tabbed device such as a TIC226.

The triac probably went short-circuit if the old bulb blew.
It is usually a metal-tabbed device such as a TIC226.- Hide quoted text -

I had one fail in exactly this way. The triac shorted as a result of
the very high current which flowed when the bulb blew and arced
internally with a bright flash and a pop. I looked up the data for the
triac. It did not have a surge rating anywhere near high enough to
survive this kind of fault, especially with the lamp close to the
consumer unit (the lamp was in the hall in our case).

B&Q replaced the first one, but refused to replace the second which
was just over a year old when the bulb blew. The manager insisted
that nobody else had ever reported such a fault and anyway they were
not obliged to replace goods more than 1 year old.

I made a token fuss in the shop, but it wasn't worth pursuing it
further for £12. I used a switch after that.

John

wrote:
The triac probably went short-circuit if the old bulb blew.
It is usually a metal-tabbed device such as a TIC226.- Hide quoted
text -

I had one fail in exactly this way. The triac shorted as a result of
the very high current which flowed when the bulb blew and arced
internally with a bright flash and a pop. I looked up the data for the
triac. It did not have a surge rating anywhere near high enough to
survive this kind of fault, especially with the lamp close to the
consumer unit (the lamp was in the hall in our case).

B&Q replaced the first one, but refused to replace the second which
was just over a year old when the bulb blew. The manager insisted
that nobody else had ever reported such a fault SNIP

Did his nose grow longer as he said it?

Bloody things are nothing but trouble.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk